R972 Trinnov User Notes - Page 8

Trinnov measures the acoustic distance of your subwoofer from the measurement position not just its physical distance. Filters in the subwoofer output circuit add electrical delay to the delay based on the physical distance. Trinnov accurately reports their sum.

Jeff

Thanks, good to know... But for all the other speakers, do you still want the physical distance -- distance being microphone to tweeter?



So in all my phase tweaking, I'm still not sure what phase setting to start with before running the Optimizer. Additionally, I have a variable phase control (0 to 180). I'm not sure how I would reverse the phase other than at the extremes.

Last, does anyone know if reversing the phase after the optimization should apply in all rooms?

Trinnov accurately measures the acoustic distance for all speakers to one one-hundredth of a meter and is time accurate to a tenth of a millisecond. So stop second guessing its capability. Put the microphone array at ear-level in your main listening position, aim the read dot where you want the center image and run a calibration. Save the results. For the subwoofer, run the calibration with the phase set to 0 degrees. After the calibration is complete, set the phase switch to 180 degrees and enjoy the music.

Jeff

P. S. You can try the phase switch in both positions. If you hear a difference, use the one you prefer.

Hi, wondering if others have noticed any bass issues with the sub when Spatial mode is active. Turning the subwoofer gain up doesn't do anything. Bass seems perfect with Trinnov EQ on, but with Spatial set to None. I tried remeasuring multiple times with the Sub's gain set at different levels.

Trinnov EQ on it's own does not set the channel levels. Channel levels are set when the spatial mode is at least set to "LVL/DLY".

Although that does not explain your problem.

You are able to get a good calculation?

Success! I finally had to keep the subwoofer level just barely high enough that it would register on the Trinnov mic. This brought the sub level on par with the rest of the speakers. My room must be reinforcing some of the bass harmonics. Once the computation was done, I turned on Flat+3D and raised the sub level dial about 6db. Now I am getting the most mesmerizing presentation I have ever heard. I watched the clips from the Disney WOW blu-ray, and I am still speechless. For the first time I've felt like I am being physically immersed into whatever movie I am watching. All credit to Trinnov and the solid pre-amp/amp on this receiver. Thanks to all for the help.

This is good to know. Thanks.

If I have multiple subwoofers and SVS AS-EQ1 and I am buying R-972, do I still need AS-EQ1?

So, if the subs are at -6 and the speakers are around -12, I need to turn up the subs with reference to the speakers, correct?

If those are the measured values shown on-screen, then your sub level is higher than the rest. Turn the sub level down and measure again until they are close to 1db to 3db from the rest of the speakers.

I put this on the Sherwood R-972 User Thread. I hope you do not mind the repeat here.

No room EQ I have tested finds the phase of the subwoofer relative to the main channels. This requires test equipment to determine if the subwoofer phase is correct. A Radio Shack meter and the Stereophile Test Disc 1 should suffice. Use the warble tone on the test disc that comes closest to the subwoofer crossover. Set the volume to achieve a reading of roughly 80dB SPL (this number should swamp room noise, but not be so loud as to require hearing protection). Note the amplitude. Now reverse the phase of the subwoofer and see if the amplitude changes. Retain the setting that achieves the higher SPL.

The test must be done with any room EQ and is not an issue with the R-972. As an aside, the R-972 will correct any phase reversal with the main channel speakers unlike many room EQs.

To achieve optimal performance from a high-end system requires software that displays the response of your room at core listening positioning, especially in the presence of a subwoofer. I use AcoustiSoft RPlusD, which reports the Radio Shack SPL meter can be used as a microphone (OK below 500Hz). There is a calibration file for the Radio Shack meter on the AcoustiSoft site. RPlusD does have a learning curve, but AcoustiSoft's on-line documentation is a great reference. Click on the link Introducing RPlusD Modal Analyzer at the top of the home page. Other, less intensive, test systems may be available. I do not have experience with them. The simpler ones may not allow multiple measurements averaging or may do it incorrectly.

David Rich

So does "not an issue with the R-972" mean it's doable, or doesn't need to be done?

You do not have to worry about any errors in wiring of the main channel speakers since the R-972 will find and correct it. Some other AVRs may not do this.

No EQ can figure out the polarity of the sub. The impulse response of the band limited sub is very different from a full range speaker. So you do have to follow the procedure I outline above to set the polarity of the subwoofer correctly.

David Rich

Are you still in the bussiness? The last time I saw your name you were working for Sensible Sound. I assumed the magazine folded since I have'nt seen any issues for a couple of years.

Thanks for your response. You provided the very information I was looking for.


I found a couple recent things by David Rich on Secrets of Home Theater and High Fidelity.

My work now appears on the Secrets of Home Theater and High Fidelity website. My technical article on the site "TVs? We Don't Need no Stinking TVs - Third-Generation Multi-channel Audio" might be of interest to you.

Before I joined the R-972 review was published by the Boston Audio Society in the Summer 2011 issue (BASSv33n2) of the B A S Speaker. This is a paper journal.

David Rich

OK thanks, I missed "main" in my reading.

I just did the setup with the following configuration:

- A pair of back speakers on the rear wall (+/-150 deg) wired to one amp

- Surrounds at +/-110 deg from front center

- Supplementary fronts at about +/-55 deg horiz and 40 deg vert

- L/R at +/-25 deg (phantom center)

Sounds quite good though I haven't watched a whole movie yet.

One thing I've noticed is that no matter what test/demo material I try I get very little from the backs.

I don't just mean that I don't hear anything from them at MLP, I mean standing at the back wall right next to them.

Actually this I can't say I've noticed them with any previous setup either.

Has anyone found the back channels to be adding anything?

To be fair, the last time I did feel backs were worth having was four receivers ago when I had Logic 7 on an HK635.

I posted the question in the other thread and it was suggested that I ask it here for better response (so I'm not intentionally double posting)

Guys,

I have been a longtime user of the P965 and just took delivery of this R972. For the life of me I cannot get Trinnov to use the rear surround speakers in playback mode. In the calibration/computation modes the rear surrounds are evident and get good readings.
The rear surrounds show up if I select Dolby Digital or Dolby EXII modes but whenever I engage Trinnov the system drops to 5.1 and not 7.1

What could I be doing wrong?

Thanks

Hi Jeff and Curt:
One of the marketing brochure says that we can download my measurements from the receiver and upload it to Trinnov's site to get graphs.. How do we do this?
Here's the blurb from the brochure...
++++++++
Performance graphs: System measurements made by the R-972 can be
saved to a USB drive. When that data is uploaded to Trinnov's site, detailed
performance graphs can be viewed, evaluated and printed. There is no limit
to the number of times an R-972 owner can use this features.
+++++++++++

It wasn't a Sherwood decision that inhibited saving Trinnov calculations to USB. In the end, TI failed to deliver the needed code.

Jeff

All Right, so I turned down the subs and got the rears installed. The Fronts, center, and sides are now at -20 dB and the sub and rears are at -15 dB. All speakers are off the same amp, but the rears are VERY close in comparison to everything else. How can I get rid of the extra 10-15 dB drop? Thoughts?

Ted

Ted:

Those are the pre-Trinnov levels. Your surrounds and sub are 5 dB louder than your L/R speakers. IMO, that is not a problem. It is rare to have all of the before measurements match. The post calibration numbers are not listed, but with Trinnov engaged they will be spot-on.

Jeff

I have some questions:

Are the feet removable from the R-972? My rack only has 8" spacing.

Can the crossovers be adjusted to say 80Hz for all the speakers with Trinnov?

Does this version of Trinnov use the same amount of taps as the Pro version?

Thanks

Would still like to hear others' experiences with this.

Curt,

Academic question: Does the 972 not allow trimming of surround levels because of cost/complexity, or is to protect from messing up the 3D soundfield?

Is this allowed in the higher end Trinnov units?

What are you using as a source? Bluray with a discrete 7.1 soundtrack?

Otherwise you'll need to use Dolby PLiix, DTS-ES or Neo 6.

There's only been 2 or 3 7.1 BD's, and I expected more based on what reviews said about the surround mix.

Dolby PLiix, DTS-ES or Neo 6 are not available with Trinnov activated.

Curt/Jeff:

What would happen in a 7-ch setup where the backs are located at the ITU surround positions, and the sides halfway between the backs and fronts?

Would the backs receive no signal with a 5.1 soundtrack per the manual, or would Trinnov 3D remapping prevail?